mirror of
https://github.com/samba-team/samba.git
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b172eb1d47
This is a security descriptor level function only.
Michael
(This used to be commit 5931540fa1
)
211 lines
5.9 KiB
C
211 lines
5.9 KiB
C
/*
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Unix SMB/CIFS implementation.
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Check access to files based on security descriptors.
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Copyright (C) Jeremy Allison 2005-2006.
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Copyright (C) Michael Adam 2007.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "includes.h"
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#undef DBGC_CLASS
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#define DBGC_CLASS DBGC_ACLS
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bool can_access_file_acl(struct connection_struct *conn,
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const char * fname,
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uint32_t access_mask)
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{
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bool result;
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NTSTATUS status;
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uint32_t access_granted;
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struct security_descriptor *secdesc = NULL;
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status = SMB_VFS_GET_NT_ACL(conn, fname,
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(OWNER_SECURITY_INFORMATION |
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GROUP_SECURITY_INFORMATION |
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DACL_SECURITY_INFORMATION),
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&secdesc);
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if (!NT_STATUS_IS_OK(status)) {
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DEBUG(5, ("Could not get acl: %s\n", nt_errstr(status)));
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return false;
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}
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result = se_access_check(secdesc, conn->server_info->ptok,
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access_mask, &access_granted, &status);
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TALLOC_FREE(secdesc);
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return result;
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}
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/****************************************************************************
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Actually emulate the in-kernel access checking for delete access. We need
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this to successfully return ACCESS_DENIED on a file open for delete access.
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****************************************************************************/
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bool can_delete_file_in_directory(connection_struct *conn, const char *fname)
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{
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SMB_STRUCT_STAT sbuf;
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TALLOC_CTX *ctx = talloc_tos();
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char *dname = NULL;
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if (!CAN_WRITE(conn)) {
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return False;
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}
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/* Get the parent directory permission mask and owners. */
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if (!parent_dirname_talloc(ctx,
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fname,
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&dname,
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NULL)) {
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return False;
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}
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if(SMB_VFS_STAT(conn, dname, &sbuf) != 0) {
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return False;
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}
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/* fast paths first */
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if (!S_ISDIR(sbuf.st_mode)) {
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return False;
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}
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if (conn->server_info->uid == 0 || conn->admin_user) {
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/* I'm sorry sir, I didn't know you were root... */
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return True;
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}
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/* Check primary owner write access. */
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if (conn->server_info->uid == sbuf.st_uid) {
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return (sbuf.st_mode & S_IWUSR) ? True : False;
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}
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#ifdef S_ISVTX
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/* sticky bit means delete only by owner or root. */
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if (sbuf.st_mode & S_ISVTX) {
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SMB_STRUCT_STAT sbuf_file;
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if(SMB_VFS_STAT(conn, fname, &sbuf_file) != 0) {
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if (errno == ENOENT) {
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/* If the file doesn't already exist then
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* yes we'll be able to delete it. */
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return True;
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}
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return False;
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}
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/*
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* Patch from SATOH Fumiyasu <fumiyas@miraclelinux.com>
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* for bug #3348. Don't assume owning sticky bit
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* directory means write access allowed.
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*/
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if (conn->server_info->uid != sbuf_file.st_uid) {
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return False;
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}
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}
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#endif
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/* now for ACL checks */
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return can_access_file_acl(conn, dname, FILE_WRITE_DATA);
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}
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/****************************************************************************
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Actually emulate the in-kernel access checking for read/write access. We need
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this to successfully check for ability to write for dos filetimes.
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Note this doesn't take into account share write permissions.
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****************************************************************************/
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bool can_access_file_data(connection_struct *conn, const char *fname, SMB_STRUCT_STAT *psbuf, uint32 access_mask)
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{
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if (!(access_mask & (FILE_READ_DATA|FILE_WRITE_DATA))) {
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return False;
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}
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access_mask &= (FILE_READ_DATA|FILE_WRITE_DATA);
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/* some fast paths first */
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DEBUG(10,("can_access_file_data: requesting 0x%x on file %s\n",
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(unsigned int)access_mask, fname ));
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if (conn->server_info->uid == 0 || conn->admin_user) {
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/* I'm sorry sir, I didn't know you were root... */
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return True;
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}
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if (!VALID_STAT(*psbuf)) {
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/* Get the file permission mask and owners. */
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if(SMB_VFS_STAT(conn, fname, psbuf) != 0) {
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return False;
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}
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}
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/* Check primary owner access. */
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if (conn->server_info->uid == psbuf->st_uid) {
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switch (access_mask) {
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case FILE_READ_DATA:
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return (psbuf->st_mode & S_IRUSR) ? True : False;
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case FILE_WRITE_DATA:
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return (psbuf->st_mode & S_IWUSR) ? True : False;
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default: /* FILE_READ_DATA|FILE_WRITE_DATA */
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if ((psbuf->st_mode & (S_IWUSR|S_IRUSR)) == (S_IWUSR|S_IRUSR)) {
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return True;
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} else {
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return False;
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}
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}
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}
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/* now for ACL checks */
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return can_access_file_acl(conn, fname, access_mask);
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}
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/****************************************************************************
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Userspace check for write access.
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Note this doesn't take into account share write permissions.
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****************************************************************************/
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bool can_write_to_file(connection_struct *conn, const char *fname, SMB_STRUCT_STAT *psbuf)
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{
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return can_access_file_data(conn, fname, psbuf, FILE_WRITE_DATA);
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}
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/****************************************************************************
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Check for an existing default Windows ACL on a directory.
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****************************************************************************/
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bool directory_has_default_acl(connection_struct *conn, const char *fname)
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{
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/* returns talloced off tos. */
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struct security_descriptor *secdesc = NULL;
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unsigned int i;
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NTSTATUS status = SMB_VFS_GET_NT_ACL(conn, fname,
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DACL_SECURITY_INFORMATION, &secdesc);
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if (!NT_STATUS_IS_OK(status) || secdesc == NULL) {
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return false;
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}
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for (i = 0; i < secdesc->dacl->num_aces; i++) {
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struct security_ace *psa = &secdesc->dacl->aces[i];
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if (psa->flags & (SEC_ACE_FLAG_OBJECT_INHERIT|
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SEC_ACE_FLAG_CONTAINER_INHERIT)) {
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TALLOC_FREE(secdesc);
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return true;
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}
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}
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TALLOC_FREE(secdesc);
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return false;
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}
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